The development and application of new methods in designing and stabilizing highly flexible wing structures for commercial transport aircraft is the main focus of the European research project FLEXOP. An unmanned, subscale flying demonstrator shall help to validate and verify these approaches in flight tests – including tests of the active flutter suppression system. German airspace regulations for the operation of Unmanned Aerial Systems (UAS) raise additional requirements to aircraft design: Since UAS flight testing has to be performed within visual line of sight, operation close to the airspeed of flutter onset increases significantly the demands on maneuverability and airspeed controllability. Since the thrust response of the integrated jet engine is proven to be impractical for dynamic airspeed control, an electric actuated airbrake is designed to provide the required control force and actuation bandwidth. In the present paper, the design of the airbrake system is shown in detail, starting from configurational constraints, to aerodynamic and kinematic design. The approach to actuator selection, testing and integration is shown. Additionally, a rapid prototyping, low-cost approach for a complete subsystem mock-up test to identify crucial parameters for controller design is presented.     «

The development and application of new methods in designing and stabilizing highly flexible wing structures for commercial transport aircraft is the main focus of the European research project FLEXOP. An unmanned, subscale flying demonstrator shall help to validate and verify these approaches in flight tests – including tests of the active flutter suppression system. German airspace regulations for the operation of Unmanned Aerial Systems (UAS) raise additional requirements to aircraft design: S...     »